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  Anisotropic extensible nonwovensUSPTO Application #: 20070254545Title: Anisotropic extensible nonwovens Abstract: This invention relates to nonwoven fabrics in which the fibers of the fabric are laid down such that a majority of the fibers have a fiber direction making an angle substantially parallel to or within an angle in a range of +/−45° of the machine direction. The invention also relates to a nonwoven fabric bonded web having bonding points in a pattern arranged along an axis perpendicular to the machine direction spaced and more widely apart than the bonding points arranged along an axis parallel to the machine direction. The resulting nonwoven having a very low elongation in the machine direction can be elongated with relatively little force in the cross machine direction. (end of abstract) Agent: Invista North America S.a.r.l. - Wilmington, DE, US Inventor: KENNETH E. MARTIN USPTO Applicaton #: 20070254545 - Class: 442328 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20070254545. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001]This invention relates to nonwoven fabrics in which the fibers of the fabric are laid down with an orientation primarily in a machine direction. The resulting nonwoven has high tensile strength and very low elongation in the machine direction, but relatively low tensile strength and can be elongated with relatively little force in the cross direction. In a process for making this nonwoven, the required fiber orientation property is obtained without a separate step of "consolidation" or "necking." BACKGROUND OF THE INVENTION [0002]Stretch nonwovens are enjoying rapid growth in the hygiene industry. The majority of products in use either have a machine direction stretch capability, such as the Kimberly Clark Demique.RTM. and "Flex-All" products or cross direction stretch such as the "Golden Phoenix" or "Tredegar" nonwoven--elastic film laminates. However, a true multi-direction stretch nonwoven provides valuable functionality to hygiene related products as well as opening new end uses such as apparel to stretch nonwovens. [0003]Commercial producers have made fully elastic multi-directional spunbond nonwovens by using elastomeric thermoplastic polymers in conventional spunbond processes. However these products, while exhibiting excellent elasticity also have an objectionable rubber like hand that is characteristic of elastic polymers. It is known to produce nonwovens with fibers oriented primarily in the machine direction by a post production "necking" or "consolidation" step in which the nonwoven is drawn in the machine direction in a separate step after it is initially produced. United States patents assigned to the University of Tennessee and related to and disclosing, in part, this technology include: [0004]U.S. Pat. No. 5,441,550 (Issued Aug. 15, 1995); [0005]U.S. Pat. No. 5,443,606 (Issued Aug. 25, 1995); [0006]U.S. Pat. No. 5,486,411 (Issued Jan. 23, 1996); [0007]U.S. Reissue Pat. No. 35,206 (Issued Apr. 16, 1996; Reissue of U.S. Pat. No. 5,244,482); [0008]U.S. Pat. No. 5,599,366 (Issued Feb. 4, 1997); [0009]U.S. Pat. No. 5,730,923 (Issued Mar. 24, 1998); [0010]U.S. Pat. No. 5,747,394 (Issued May 5, 1998); [0011]U.S. Pat. No. 6,030,906 (Issued Feb. 29, 2000). [0012]In view of the disclosures of the prior art it remains clear that the necking or consolidation processes provide a nonwoven product with at least the desirable cross direction extensibility. This cross direction extensibility is obtained after a second step following production of a nonwoven. The added costs of this step to the overall process are a deficiency to an economically viable route to the product. SUMMARY OF THE INVENTION [0013]Herein disclosed is an invention providing a cross directionally extensible nonwoven produced directly without a consolidation or necking step. [0014]The nonwoven provided by the process herein disclosed has substantially different physical properties in the machine direction versus the cross direction characterized in that said nonwoven has a cross direction elongation at break of at least about 50 percent. Substantially different physical properties refer to at least the elongation without rupture in the machine direction and the perpendicular direction. [0015]The nonwoven provided in an embodiment herein has a cross direction elongation at break of about 100 to about 200 percent. [0016]The nonwoven provided in embodiments herein is selected from the group comprising spunbonded, melt blown, carded thermal bond, and spunlaced structures. [0017]Provided by the disclosures herein is a process for making a nonwoven having substantially different physical properties in the machine direction versus the cross direction comprising the steps of: laying down a fibrous web, followed by bonding the web. The process provided substantially aligns the fibers of the nonwoven in the machine direction and bonds the resulting web such that the resulting material has cross direction extensibility but with sufficient cross directional and machine directional coherence to allow subsequent conversion steps. [0018]Provided in an aspect of the invention is a process for making an extensible nonwoven comprising the steps of laying down a fibrous web and bonding the web by selecting a bonding pattern comprising a small number of bonding points and wherein, the bond points arranged along an axis perpendicular to the machine direction are spaced more widely apart than the bond points arranged along an axis parallel to the machine direction and wherein the bond points are provided by thermal energy. [0019]Provided in an aspect of the invention is a process for making an extensible nonwoven comprising the steps of aligning carded bats of fibers such that a majority of the fibers have a fiber direction making an angle substantially parallel to or within an angle in a range of +/-45.degree. of the machine direction and bonding the web. DEFINITIONS [0020]The following non-limiting definitions comprise a glossary of stretch nonwoven technology terms. These definitions are meant to guide the skilled person to a clear and concise meaning for the various terms of art as used herein. Continue reading... Full patent description for Anisotropic extensible nonwovens Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Anisotropic extensible nonwovens patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Anisotropic extensible nonwovens or other areas of interest. ### Previous Patent Application: Method for disinfecting a non-porous textile fabric and a disinfected, non-porous textile fabric Next Patent Application: Nonwoven textile assembly, method of manufacture, and spirally wound press felt comprised of same Industry Class: Fabric (woven, knitted, or nonwoven textile or cloth, etc.) ### FreshPatents.com Support Thank you for viewing the Anisotropic extensible nonwovens patent info. IP-related news and info Results in 1.51198 seconds Other interesting Feshpatents.com categories: Qualcomm , Schering-Plough , Schlumberger , Seagate , Siemens , Texas Instruments , |
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